1. Field of Invention
The present invention relates to finishing machines, being especially adapted for use in or with vibratory finishing machines and particularly those having a curvilinear finishing chamber and vertically oriented gyratory motion-producing assembly and power driving means.
2. Prior Art
Finishing machines and especially vibratory finishing machines are well known in the art. Such machines are used for various forms of finishing, such as burr removal, burnishing, and polishing. Such machines are disclosed and claimed in U.S. Pat. Re. Nos. 27,084, 3,400,495, 3,423,884, 3,435,564, 3,466,815, 3,606,702, and 3,633,321. Machines of the type described generally have a finishing chamber and a motor operatively mounted with respect to the chamber and arranged to cause eccentric weights to rotate or revolve, thereby producing vibratory motion of the finishing chamber. In one form disclosed in the prior art, a tub-type of finishing chamber, usually linear, has a motor with eccentric weights mounted on the shaft of the motor directly mounted to the tub, or a shaft with eccentric weights mounted to the tub and motor driven. In another type, the eccentric weights are mounted out of phase on a vertical shaft, causing the finishing chamber which is generally curvilinear to undergo gyratory motion. In either type, as a result of the vibratory movement, when materials such as parts and/or finishing materials are placed in the chamber, orbital motion is imparted to the contents so that they move upwardly at the peripheral portion of the chamber and downwardly at the inner portion of the chamber. This results in relative movement between the finishing material and parts, or at least interaction therebetween, causing the parts to be finished. Additionally, by employment of a proper phase relationship between the eccentric or unbalance weights, varying degrees of precession or linear progression of the material and parts are caused circumferentially around the annular finishing chamber, or linearly in the tub-type, as is well-known in the art. Various forms of guides or vanes, including helical guides, have also been fixed internally of a finishing chamber to assist with such precession. See, for example, U.S. Pat. No. 3,071,900.
Prior art finishing machines, e.g., tumbling machines and vibratory finishing machines, such as described above, generally function well. However, they all suffer from at least one disadvantage. During the finishing process, there is a tendency for closely adjacent parts to collide with each other as a result of the tumbling or vibrational movement imparted to them, often resulting in considerable damage to the parts by denting or fracture. In U.S. Pat. No. 3,423,884, a finishing apparatus is disclosed wherein the entire finishing machine may be mounted for rotation by an adjoining motor and belt assembly. The finishing chamber is divided into a plurality of compartments which are stationary with respect to the finishing chamber, the entire assembly if desired rotating during the finishing process. This apparatus succeeds in isolating high precision and easily damageable parts so that they are safely finished. However, no unloading means have been provided or suggested for such machine and it is necessary that each part be unloaded by hand. The cost of labor utilized in manually loading of parts, separating parts from finishing media, and hand removal of finished parts from the finishing machine is extremely high, if not prohibitive. Finishing machines have also been devised utilizing spindles, wherein the parts are fixtured to a spindle during the finishing process. The cost of manually mounting the parts and removing them in such devices is also prohibitively high. Floating compartment devices are also known, but these are no better than fixed compartment machines and suffer from the same disadvantages as previously noted, e.g., the necessity of manual loading and separation and the high cost of labor associated therewith in the absence of any suggestion of automatic separation and how it might be effected in such devices.
As known in the art, parts-finishing cycle control or adjustment has been effected by controlling the phase relationship of the eccentric weights on the shaft driven by the motor. U.S. Pat. Nos. 3,435,564 and 3,466,815 show means for making such adjustment. This is a partially satisfactory way of operation, but it has the limitations that it does not permit precise or exact control of the parts-finishing cycle, and further, that it does not keep the parts evenly distributed in the finishing chamber. The method and apparatus of the present invention, on the other hand, does permit precise and exact control of the parts-finishing cycle, and does permit isolation of parts from other parts to prevent damage to the parts as a result of collision between them.